Morphological Effects of Root Pruning and Wrenching White Spruce Transplants

1988 ◽  
Vol 5 (4) ◽  
pp. 245-247
Author(s):  
Lisa J. Buse ◽  
Robert J. Day

Abstract The principal objective of this research was to evaluate the effect of root pruning followed by wrenching on the morphological quality of 2 + 2 white spruce transplant stock during the final year on the nursery. In 1984, white spruce transplants were root pruned: (1) before shoot elongation; (2) during elongation; and (3) after elongation, followed by root wrenching at 28-day intervals until September (4, 3, and 2 times, respectively). In 1985, similar stock was root pruned before shoot elongation and (1) root wrenched at 21-day intervals (4 times), and (2) root wrenched periodically (twice). In both years, height and root collar diameter growth were monitored throughout the season. In the fall, morphological quality was assessed and bud samples were collected to determine the effects of root conditioning on primordia development. Root conditioning modified the morphology of stock in both years by reducing height and root collar diameter and inducing the development of a compact fibrous root system. Early season root pruning followed by wrenching at regular intervals throughout the growing season had the most effect on shoot and root morphology. Differences in results between years were attributed to environment. North. J. Appl. For. 5:245-247, December 1988.

2017 ◽  
Vol 59 (4) ◽  
pp. 281-286
Author(s):  
Maria Hauke-Kowalska ◽  
Winicjusz Kasprzyk

AbstractPruning is one of the important cultural treatments that have potential to influence hardwood seedling morphology. The aim of the study was to compare the growth of pedunculate oak seedlings, performed pruning roots, in the second growing season, fertilised full and reduced dose of nitrogen.A total of 24 experimental plots, each with an the area of 0.04 ha, were designated. The roots pruning were made at the end of February 2014 using root pruning machine EGEDAL. The fertilisation, for all seedlings, was performed using ammonium nitrate in an amount of 25 kg ha−1of nitrogen. The second fertilisation was performed only for variants 2 and 4. For these variants, urea was used in an amount of 25 kg ha−1. At the end of the growing season, the root collar diameter and the height of seedlings were measured.A dose of nitrogen affects the height of pruned seedlings. The effect of the full dose of nitrogen on the height of the pruned seedlings was a statistically significant (p≤ 0.05). There was no statistical difference in the height of the seedlings without pruning, fertilised with different dose of nitrogen.Analysis of root collar diameter showed the significant differences between the variants. The Tukey test, at the significance level ofp≤ 0.05, showed a significant impact on the root collar diameter of pruned seedlings but no proven effect of nitrogen fertilisation. To conclude, we found that it is reasonable to reduce the doses of nitrogen fertilisation to half of recommended amount (25 kg ha−1) if the root system is not pruned during the second growth year. Seedlings that has received pruning should be fertilised using the recommended doses of nitrogen.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Kupatsa Mtambalika ◽  
Chimuleke Munthali ◽  
Dominic Gondwe ◽  
Edward Missanjo

Afzelia quanzensisWelw is a valuable timber producing tree species in Africa. A study was conducted to evaluate the influence of seed size on seed germination and seedlings quality ofAfzelia quanzensis. Seed was categorized into three groups in regard to their length, small (<1.5 cm), medium (≥ 1.5 ≤ 2.5 cm), and large (>2.5 cm). The treatments were completely randomized into four replications. Germination percentage was not significantly(P>0.05)different between the treatments, although large seeds had the highest germination percentage of 94.9%. There were significant(P<0.05)differences in seedling height and root collar diameter among the different seed sizes, with large seeds having the highest seedlings height and largest root collar diameter. This was attributed to differences in the food reserves. Survival of transplants from shoot dieback was significantly(P<0.05)different such that seedlings from large seed attained the highest survival of 92%. It is therefore recommended that, for production of high quality transplants in the nursery, large seeds should be used.


1960 ◽  
Vol 36 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Alexander Dickson ◽  
Albert L. Leaf ◽  
John F. Hosner

Total seedling weight, shoot weight and root weight in grams on an oven dry basis, root collar diameter in millimeters, and height in centimeters were used to develop an integrated index of seedling quality.


2000 ◽  
Vol 76 (5) ◽  
pp. 775-782 ◽  
Author(s):  
G. Geoff Wang ◽  
J. Aurea Siemens ◽  
Vince Keenan ◽  
Daniel Philippot

Differences in survival and growth of black and white spruce seedlings planted on boreal mixedwood sites were tested for stock types (transplant versus container), site preparation (Donaren disc trenching versus no trenching), and plantation types (open versus sheltered) in southeastern Manitoba after eight or nine growing seasons. Mortality of open plantation (32.3%) and container stock (32.5%) were significantly higher than sheltered plantation (23.7%) and transplant stock (22.8%), respectively. Donaren trenching slightly reduced the mortality of black spruce but significantly increased the mortality of white spruce. Seedlings of container stock (110 cm) were significantly shorter than transplant stock (157 cm). Significant difference in height was found between open and sheltered plantations for black spruce but not for white spruce. Root collar diameter of container stock (15.6 mm) was significantly smaller than transplant stock (23.1 mm). Root collar diameter in sheltered plantations was significantly larger than that in open plantations for black spruce but not for white spruce. Black spruce open plantation had significantly smaller volume (97 cm3) compare to black spruce sheltered (210 cm3) and white spruce open (175 cm3) and sheltered (229 cm3) plantations. White spruce open plantations also had smaller volume than white spruce sheltered plantations. Container stock had smaller volume (89 cm3) than transplant stock (267 cm3). For transplant stock, strip plantations had a significantly higher volume (329 cm3) than open plantations (204 cm3). Based on above results, we recommend that (1) transplant stock should be used, (2) sheltered plantation site preparation should be used on boreal mixedwood sites, and (3) Donaren disc-trenching is not necessary for planting white spruce. Key words: silviculture, boreal mixedwood site, plantation


2010 ◽  
Vol 59 (1-6) ◽  
pp. 151-158 ◽  
Author(s):  
Deogratias M. Rweyongeza ◽  
Francis C. Yeh ◽  
N. K. Dhir

AbstractWe estimated heritabilities and correlations for bud flushing and growth traits of white spruce seedlings, and the correlations of seedling traits with 10- and 11- year height of the same families in the field. The seedling greenhouse experiment had a randomized complete block design with 30 replications, 58 open-pollinated families and single-tree plots. Individual tree heritability (hi2) was 0.78 and 0.54 for 18 (H18) and 36 (H36)-week total height, respectively. The corresponding heritabilities for family means (hf2) were 0.91 and 0.82. For root collar diameter, hi 2 were respectively, 0.61 and 0.22 at 24 and 54 weeks from germination. The corresponding hf2were 0.87 and 0.55. Heritability for bud flushing ranged from 0.13 to 0.46 (hi2) and 0.44 to 0.83 (hf 2). The genetic correlation (ra) between H18 and H36 was 0.70 and that of D24 and D54 was 0.89, indicating a substantial change in family ranking in one growing season. The type B genetic correlation for H18 with field heights ranged from 0.22 to 0.30. Type B genetic correlations of field height with all other seedling traits were very low and largely negative. It can be concluded that: (1) age-age correlation of seedling height can be expected to decline drastically even in a stable environment of the greenhouse, (2) heritability for growth potential is meaningful when estimated on cumulative growth not on individual annual growth increments that are susceptible to short-term environmental variation, (3) dates of bud flushing did not influence variation in height and root collar diameter, and (4) field growth potential is better predicted by greenhouse growth potential than other morphological and shoot phenological traits.


REFORESTA ◽  
2020 ◽  
pp. 25-30
Author(s):  
Jovana Devetaković ◽  
◽  
Lučian Krinulović ◽  
Ivona Kerkez Janković

Austrian pine (Pinus nigra Arnold) seedlings are frequently used for afforestation/reforestation and restoration practice in Serbia. Indeed, the seedlings of various stock types are produced by almost all forest nurseries in Serbia and bareroot seedlings are mostly common. The aim of this study is to analyze the method of sowing and sowing density on some morphological characteristics and quality of one-year-old Austrian pine seedlings. Sowing in rows and random sowing across all seedbed space were performed. In both cases, the sowing density (R1 - 8 g m-1, R2 - 40 g m-2) and half of the recommended sowing density (S1 - 4 g m-1, S2 - 20 g m-2) were applied. Seedlings from both treatments had average height and root collar diameter values in the range of 4.91 to 5.73 cm, and 1.25 to 2.34 mm, respectively. Observed characteristics of seedlings (height - H, root collar diameter - RCD, root length - RL, dry weight of shoot - SDW, root - RDW and seedlings - SLDW, sturdiness coefficient - SQ and quality index - QI) were conditioned by treatment (One-Way ANOVA, p<0.05). Shoot to root ration was similar at seedlings of all treatments and ranged from 1.33 to 1.63. In both cases, decreased density produced better results. The combination of lower sowing density (20 g m-2) and sowing in all seedbed areas (S2) provided the best seedlings with QI - 0.21.


2016 ◽  
Vol 77 (3) ◽  
pp. 256-260
Author(s):  
Winicjusz Kasprzyk ◽  
Szymon Jastrzębowski

Abstract The aim of this study was to examine the effects of pruning the root system and different doses of nitrogen fertilization on the height and root collar diameter of 2-year-old beech seedlings (Fagus sylvatica L.). This research was conducted in the forest nursery Muchów (Jawor Forest District, regional directorate of State Forests in Wrocław) and two different pruning treatments (no pruning and at 12 cm depth) and nitrogen fertilization doses (25 and 50 kg×ha−1) were applied. Results from an ANOVA showed statistically significant differences between the two pruning treatments (p = 0.000) as well as for the interaction of both treatment factors (p = 0.019). Root collar diameter correlated with seedling height, both of which were significantly different for the two pruning treatments (p = 0.000). No statistically significant impact by the nitrogen fertilization doses on seedling height could be observed (p = 0.125). To conclude, we found that it is reasonable to reduce the doses of nitrogen fertilization to half the recommended amount, 25 kg×ha−1, if the root system is not pruned during the second growth year. Seedlings that do receive pruning should be fertilized using the recommended nitrogen doses.


2019 ◽  
pp. 23-31
Author(s):  
Vladan Popović ◽  
Aleksandar Lučić ◽  
Ljubinko Rakonjac ◽  
Ivona Kerkez-Janković

The paper analyzes the morphological quality parameters of one-year-old sessile oak (Quercus petraea (Matt.) Liebl) seedlings and their interrelations. Based on the performed analyzes, it was determined which of the measured morphological parameters, with minimal time and resources spent, gives the most accurate estimate of the quality of one-year old seedlings. For the conducted research, seedlings were produced in the nursery of the Institute of Forestry in Belgrade, in uniform environmental conditions from seed collected in seed stand RS-2-2-qpe-22-169. The seedlings were produced in the same nursery seedbed, and the sample for analysis was taken by dividing the seedbed into four sections and taking 30 seedlings from each section by random sampling. The following morphological parameters were measured: root collar diameter, height of seedlings, weight of above and underground part of seedling in absolutely dry condition and root volume. Based on the measured values, height ratios were calculated as follows: height:root collar diameter, weight of aboveground part of seedling: weight of underground part of seedling, and quality index. The height of the seedlings and root collar diameter are good indicators of quality, which is confirmed by the positive correlative relationships with other measured morphological parameters. A stronger dependence has been found in the root collar diameter, especially with the quality index, so it can be recommended as a good indicator of the quality of the one-year old sessile oak seedlings. The quality index has been confirmed as the most comprehensive morphological indicator of the seedling quality.


1984 ◽  
Vol 60 (6) ◽  
pp. 345-355 ◽  
Author(s):  
R. van den Driessche

In three experiments coastal and interior varieties of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Sitka spruce (Picea sitchensis (Bong.) Carr), white spruce (Picea glauca (Moench.) Voss), lodgepole pine (Pinus contorta var. latifolia Engelm) and western red cedar (Thuja plicata Donn.) were grown at a range of spacings, within drills 15 cm apart, at four nurseries in coastal British Columbia. In a fourth experiment the frequency distribution of seed spacings achieved with three types of precision seeders was examined.A 1 cm increase in spacing increased seedling dry weight by 0.5–1.5 g and root collar diameter by 0.2–0.25 mm. up to a spacing of about 8–10 cm. Above this spacing response was less. Height of two-year old (2-0) seedlings was increased little, or even decreased by wider spacing. Height:diameter ratios decreased sharply and shoot:root dry weight ratios decreased or remained unchanged with wider spacing. The number of needle primorida in 2-0 Douglas-fir buds increased up to a spacing of 2 cm. The number of first and second order branches was also increased in 2-0 seedlings of this species by wider spacing. Needle dry weight and area measurements suggested Douglas-fir from wider spacing had more sun type needles than those from closer spacing, which had more shade type needles. Only small increases in root growth capacity (RGC) were associated with wider spacing. None of the precision seeders tested achieved anything like perfect precision of seed placement. With irregularity added by 10–20% non-viable seed and winter mortality, truly precision spaced stands of 2-0 seedlings could not be achieved under existing conditions. Increased spacing of 2–5 cm between seedlings, depending on species and nursery, was justified by yield of acceptable seedlings when culling standard was increased to a root collar diameter of about 6 mm.Three years after planting, survival of white spruce was increased 11% by wider spacing in the nursery, and the corresponding value for Sitka spruce two years after planting was 13%. Seedlings of both species from wider spacings maintained a height and diameter advantage over those from close spacing.


Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Fangfang Wan ◽  
Amy L. Ross-Davis ◽  
Wenhui Shi ◽  
Christopher Weston ◽  
Xiehai Song ◽  
...  

Subirrigation (SI), where water is provided to container seedlings from below and rises through the growing media via capillary action, is regarded as an environmentally-responsible method of delivering water and fertilizer to nursery-grown plants, resulting in more uniform crops and improved production efficiency. While a concern around adopting this method is that a potential higher salt concentration in the upper layers of growing media under SI may inhibit root growth and result in decreased plant quality, few studies have focused on how root morphology is altered by SI. Therefore, a balanced two-factor factorial design with three rates of fertilization (50, 100, and 150 mg N seedling−1) and two irrigation methods (SI or overhead irrigation (OI)) was used to examine the growth response of Prince Rupprecht’s larch (Larix principis-rupprechtii Mayr) seedlings for one nursery season. Associated changes between rhizosphere electrical conductivity (EC) and root morphology of different root size classes were analyzed. Results show that (1) height, root-collar diameter, and root volume were similar between seedlings grown under SI and OI. However, (2) compared to seedlings receiving OI, SI-seedlings had less root mass, length, and surface area but greater average root diameter (ARD). (3) Morphological differences were evident primarily in root diameter size classes I–III (D ≤ 1.0 mm). (4) Fertilizer rate influenced root length and surface area up to 130 days after sowing but affected ARD throughout the growing season such that seedlings treated with 50 mg N had smaller ARD than seedlings treated with 100 mg N. (5) As the growing season progressed, SI-media had significantly higher EC compared to OI-media and EC increased with increasing fertilizer rate under SI but not under OI. These results indicate that SI can produce larch seedlings of similar height and root collar diameter (RCD) compared to OI, but root systems are smaller overall with fewer small-diameter roots, which may be related to high EC levels in SI-media, which is exacerbated by the use of high rates of fertilizer. Therefore, the EC in the media should be monitored and adjusted by reducing fertilizer rates under SI.


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